In exploring the themes of change and multiple levels of analysis, the research projects described in this TPRC will utilize complex study designs and will require sophisticated procedures for sampling, measures development, and collection, management, statistical analysis, and reporting of data. The Statistics Core will provide services and consultation for every aspect of those research activities. The Statistics Core will maintain a web-based system for data entry, data management, interactive statistical analysis, and dataset storage. Core members will help the investigators to analyze and interpret their data using the most appropriate statistical techniques. The Statistics Core also will provide training and pursue collaboration opportunities with center investigators and personnel. The Specific Aims of the Statistics Core are the following: 1. Design and Sampling: To assist in the review of research design protocols and to develop and implement appropriate sampling methodology for TPRC projects. 2. Measurement: To assist in the development and validation of new psychosocial measures required by the research projects, thereby enhancing the psychometric properties of the surveys and ensuring their conceptual and psychometric equivalence across cultural groups. 3. Data management: To streamline data entry and management by designing and implementing web-based data entry, management, and analysis systems. 4. Statistical Analysis: To provide statistical and computer support for Center research projects and to provide an interface between Center investigators and statistical resources. 5. Training: To enhance transdisciplinary skills by training TPRC investigators, staff, and research assistants in analytic methodologies from collaborating disciplines (e.g., social network analysis, multilevel modeling, cross-cultural validation, implicit cognition analysis).